1. Field of the Invention
The present invention relates to a server/client system, an information processing unit, an information processing method, and a computer program. More particularly, the present invention relates to a server/client system, an information processing unit, an information processing method, and a computer program for implementing an efficient content-use management configuration when content stored in a server are copied to and used in a client such as a portable device, etc.
2. Description of the Related Art
In recent years, large-volume storage media, such as digital video discs (DVDs), the Internet, broadband communication networks (xDigital Subscriber Lines (xDSLs), cable TVs (CATVs), wireless networks, etc.), etc., have been developed and digital recording/reproducing apparatuses have become widespread. Thus, digital data, such as music data and image data, etc., has been distributed and used widely.
In general, distribution rights and the like, of many types of content, such as music data, image data, etc., are possessed by the creators or the dealers of such content. However, digital data can be recorded and reproduced without deteriorating the image and the sound of the original data, and thus the incidence of so-called distribution of pirated-edition discs, for example, distribution of illegally copied content through the Internet, copying content onto CD-Rs, etc., has become rampant;.
In order to prevent, such illegal copying of content, when content protected by copyright is distributed, it is common to impose certain conditions and restrictions on the use of the content. Thus, various systems and methods for restricting use of the content is employed, for example, only legal users are permitted to use the content by encrypting the content, and settings are established to restrict copying in order not to permit the production of a large number of copies. Such copy restrictions include, for example a setting to prohibit generation of all copies, a setting to permit only a single-generation copy, etc.
Content protection control is usually performed based on a certain rule. For example, when content to be copied, which is permitted to be copied a certain number of times, is transferred between devices, authentication among devices is performed to confirm the validity of a device on which the content is output. For example, Japanese Unexamined Patent Application Publication No. 2001-243707 has disclosed a configuration in which authentication processing is performed among the devices and content is output depending on the authentication result when a personal computer and a portable audio player, etc., are connected by a USB cable, etc., and copy data of copyrighted content such as audio data is output from the personal computer to the portable audio player.
Under Copyright Law, content, as the work of authors, is protected from illegal uses such as unauthorized reproduction and alteration. On the other hand, legal users of author's works are allowed to reproduce the content for personal use, that is to say, personal use at home and for a limited range of equivalent uses (See Article 30 of the Copyright Law).
However, when content is prohibited to be copied or the number of times it can be copied is restricted, as described above, various inconveniences occur in the above-described private use of that content. For example, when copy-prohibited content is recorded in a specific medium (for example, a DVD), a problem arises in that it becomes difficult for a device incapable of reproducing that medium (DVD), such as a portable device using a semiconductor memory as a recording medium, to use that content. Also, there is a problem in that free use of content, for example storing content recorded in a hard disk of a certain device into a hard disk of another device to use it, is not allowed.
A user sometimes legally obtains content from, for example a storage medium such as a DVD or from a server on the Internet, stores that content into a server connected to his/her home network, and then outputs a copy of the content to another terminal (client) possessed by that user, such as his/her mobile terminal, in order to enjoy the playback of that content while out of the house. Such a style of usage of content is regarded as within the permissible range of private use, and thus the content should be permitted to be copied and used. However, if content is prohibited to be copied or the number of times the content can be copied is restricted, as described above, or if copying of content has been carried out once, there arises a problem in that it becomes possible to use the content only on a device capable of using the medium in which that content is recorded.
As described above, if strict restrictions are imposed on the use of content, the convenience for a user's private use, which is originally admitted under Copyright Law, is impaired.